This invention pertains generally to synergistic blends of phosphites and hindered phenols with or without other additives as stabilizers for polymers.
The invention described herein pertains generally to synergistic blends of certain phosphites and hindered phenols as stabilizers for polymers. These blends may be used with other polymer additives.
Various prior art references teach the incorporation of additives into organic polymeric materials. These additives can include polymer stabilizers such as antioxidants, UV absorbers and light stabilizers, metal deactivators, peroxide scavengers, basic co-stabilizers, lactones, nucleating agents, fillers and reinforcing agents, aminoxy propanoate derivatives, plasticizers, lubricants, emulsifiers, pigments and dyes, optical brightners, flame-proofing agents, antistatic agents, blowing agents, cross-linking agents, antiblocking agents, slip agents, processing aids, and thiosynergists.
In particular, certain phosphites have been used in combination with hindered phenols as additives in polymers for stabilization against thermooxidative deterioration.
What is illustrated in this invention are novel blends of phosphites and hindered phenols useful as polymer additives. The novel blends of phosphites and hindered phenols of this invention show superior performance in stabilizing polymers against thermooxidative deterioration as compared with prior art phosphite/hindered phenol blends.
In accordance with the present invention, there is provided a composition useful as a polymer additive comprising a blend of bis-(2,4-dicumylphenyl) pentaerythritol diphosphite, optionally, one or more additional phosphites, and one or more hindered phenols. As compared with prior art phosphite/hindered phenol blends, the blends of this invention show unexpectedly superior performance in stabilizing polymers against thermooxidative deterioration during processing as indicated by melt flow index.
It is therefore an object of this invention to provide blends of phosphites and hindered phenols comprising bis-(2,4-dicumylphenyl) pentaerythritol diphosphite, said blends being useful, when added to polymers, as stabilizers against thermooxidative degradation during processing of a polymer composition comprising the polymer and the blend.
In general, the present invention provides a composition which comprises bis-(2,4-dicumylphenyl) pentaerythritol diphosphite, optionally, at least one additional phosphite; and at least one hindered phenol antioxididant.
This and other objects of this invention will be evident when viewed in light of the drawings, detailed description, and appended claims.